1. Field of the Invention
The present invention relates to an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.
2. Description of the Related Art
Due to advantages such as low price and high productivity, electrophotographic photosensitive members providing a photosensitive layer (organic photosensitive layer) which uses an organic material as a photoconductive material (a charge generating material and a charge transporting material), a so-called “organic electrophotographic photosensitive member”, on a support are becoming more widespread as an electrophotographic photosensitive member. Due to advantages such as high sensitivity and variety in material design, electrophotographic photosensitive members having a multi-layer photosensitive layer composed of a charge generating layer containing a charge generating material and a charge transporting layer containing a charge transporting material, a so-called “multi-layer photosensitive layer”, predominate for organic electrophotographic photosensitive members. Examples of the charge generating material include photoconductive dyes and photoconductive pigments. Examples of the charge transporting material include photoconductive polymers and photoconductive low-molecular weight compounds.
Electrophotographic photosensitive members are subjected to direct application of electrical external forces and/or mechanical external forces on their surface, such as of charging, exposure, development, transfer and cleaning, and hence are required to have resistance to these. Specifically, electrophotographic photosensitive members are required to have durability against the scratching and wear of a surface caused by a cleaning blade or paper, friction memory properties against light, friction memory properties against frictional electrification with abutting members, resistance to cracks and depressions caused by abutting members, and adhesion resistance to toner.
One of the various above-described problems is the phenomenon of “friction memory”. This phenomenon is one memory phenomenon which is caused by plus charge being generated on a photosensitive member surface as a result of the photosensitive member and a charge member or cleaning blade abutting the photosensitive member rubbing against each other when subjected to vibration from distribution or receiving a shock from a fall.
In view of such a problem, Japanese Patent Application Laid-Open No. H10-142813 discusses a technique for reducing the friction with a cleaning blade by introducing a phenyl group which has fluorines substituted on the terminals of the binder. Japanese Patent Application Laid-Open No. 2000-075517 discusses a technique for suppressing the occurrence of memory by combining a charge transporting material with a specific structure and a polycarbonate resin with a specific structure.
Further, from the perspective of reducing the friction between a photosensitive member and a charge member or blade, changing the surface profile of the photosensitive member can be thought of as one means. For example, Japanese Patent Application Laid-Open No. 2001-066814 discusses a technique for subjecting the surface of an electrophotographic photosensitive member to compression molding using a stamper provided with well-shaped uneven portions.